During the summer of 1968 a U.S. Geological Survey expedition led by Eugene M. Shoemaker retraced the historic 1869 and 1871 river voyages of Major Powell, in order to reoccupy the camera stations of the 1871 voyage and rephotograph the same scenes nearly 100 years later. Remarkably enough, about 150 camera stations were recovered, many requiring considerable search, and official photographer Hal G. Stephens rephotographed the scenes taken with cumbersome wet-plate cameras nearly 100 years earlier by E. O. Beaman (above the site of Lees Ferry) and by J. K. Hillers (below the site). A report containing these remarkable sets of before and after photographs hopefully will be published eventually as a delayed part of the Powell centennial. A few pairs have been published by others (Baars and Molenaar, 1971, p. 90-99), and two pairs are shown herein as figures 62 and 67. As these photographs show, in most places the rocks and even the vegetation remain virtually unchanged after nearly a century, but a few other pairs not included herein show catastrophic changes resulting from local floods or rockfalls. [Illustration: CANYONLANDS NATIONAL PARK, showing location in Utah, Lake Powell, Dead Horse Point State Park, boundaries, streams, roads, trails, landforms, and principal named features. There was insufficient room to show all named features; some not shown are related in text by distance and direction to named ones, and some additional names are given in figures 7, 51, and 59. Hans Flat Ranger Station near left border is in Glen Canyon National Recreation Area. The reader is referred to road maps issued by the State or by oil companies for the location of U.S. Highway 163 (shown as 160 on old maps) and other nearby roads and for the locations of the towns of Green River, Crescent Junction, Moab, La Sal Junction, and Monticello. Visitors also can obtain pamphlets at the entrance stations to the Needles and Island in the Sky districts of the park or at the National Park Service office in Moab; these contain up-to-date maps of the park and the latest available information on roads, trails, campsites, and picnic sites. (Fig. 1)]